The total mushroom production in Korea in 2015 comprised about 200,000 ton with a value of about 700 billion won (one trillion won if mushroom factory products are included, 1 $=1,128 won). This is almost equal to the amounts generated by flowers and medicinal crops. Even though the cultivation area and the number of farms have been decreased since 2006, the scale of the farms is increasing. Also mushroom productivity and consumption (4.9 ㎏ / person in 2015) are steadily increasing. Major cultivated species are Flammulina velutipes, Pleurotus ostreatus, Pleurotus eryngii, Lentinula edodes and Agaricus bisporus, which cover 90% of the total production. Shelves, logs, plastic bags or plastic bottles are mostly used for cultivation depending on the kind of mushroom. Mushroom export estimated about 43 million $ in 2016. Major exported mushrooms are Flammulina velutipes, Pleurotus eryngii, Lentinula edodes, Pleurotus ostreatus, Tricholoma matsutake and Agaricus bisporus that are destined for the U.S., the Netherlands, Australia, Canada, Hong Kong, Japan and several other countries. Mushroom research in the RDA started in 1967. In the beginning, development of cultivation methods using rice straw was studied together with distribution of improved strains of the button mushroom. The costs of button mushroom production strongly increased due the improving national economy, shortage of workers, increase of wages and the oil crisis in the nation. This caused a weak competitive position for button mushroom export and resulted in reduction of the button mushroom cultivation area. After development of a cotton waste cultivation method for the oyster mushroom (Pleurotus ostreastus), this mushroom was popularized and mainly studied. Development of automated plastic bottle cultivation systems in the 1990s changed shelf cultivation to mass production. The bottle system was applied to the oyster mushroom but also to F. velutipes and P. eryngii. Mushroom research in the RDA nowadays focuses on analysis of mushroom genetics in combination with development of new mushroom varieties, mushroom physiology and cultivation. Further studied are environmental factors for cultivation, disease control, development and utilization of mushroom substrate resources, post-harvest management and improvement of marketable traits. Finally, the RDA manages the collection, classification, identification and preservation of mushroom resources.

In present work, manufacturing technologies of titanium hydride powder were studied for recycling of titanium tuning chip and for this, attrition ball milling was carried out under H2 pressure of 0.5 MPa. Ti chips were completely transformed into TiH2 within several hundred seconds. Dehydrogenation process TiH2 powders is consist of two reactions: one is reaction of TiH2 to TiHx and the other decomposition of TiHx to Ti and H2. The former reaction shows relatively low activation energy and it is suggested that the reaction is caused by introduction of defects due to milling.

Manufacturing technologies of micro parts were studied in nano grained Al-1.5mass%Mg alloy. During compressive test at 300 , the Al alloy showed stain softening ℃ phenomenon by grain boundary sliding regardless of strain rate. Micro spur gear with ten teeth (height of 200 μm and pitch of 250 μm) was fabricated with sound shape by micro forging. During micro forging, increase of applied stress induced by friction between material and die surface was effectively compensated by decrease of stress by strain softening behavior and as a result, flow stress increased only about 50 MPa more than that in compressive test.

A rapid chemical dewatering of the in-situ hydraulically dredged coastal sediment suspensions treated with cationic cetyl-trimethyl-ammonium-bromide (CTAB) was investigated. The dewatering process consisted of coating or adsorption of the surfactant on the surface of sediment to change its hydrophobicity and hexane spraying to enhance moisture removal from the sediment surface. The dredged wet sediment sample was wet-sieved with the #450 sieve (32 μm) and synthetic sea-water made of bay salt (3.5%). The sieved sediment was settled and then freeze-dried. Considering the field process, the freeze-dried sediment was pre-treated by adding 5 M H2O2 and 0.5% Tween 80 to remove organics in the sediment and then adding 0.5% alum and 0.001% PAC for flocculation. The mean water content of the pre-treated sediment was 55.8~59.1%. The CTAB dosage was in the range of 0.001 to 1.0 g per 10 g of the pre-treated sediment (0.01 to 0.10 (wt/wt) of CTAB/sediment ratio). After addition, the sediment and CTAB mixture was mixed thoroughly by using a vortex followed by freeze-dried. For hydrophobicity test, 0.5 g of the freeze-dried samples were taken into the two-layer solutions mixed with hexane (20 mL) and deionized water (20 mL). The higher amount of the samples were migrated into the hexane layer as the CTAB dosage increased to 0.1 g (Fig. 1), indicating that the surface charge of the sediment was neutralized by electrostatic attraction of negative charged sediment particles with cationic CTAB. The additional dosage of CTAB to 1.0 g per 10 g sediment led to transfer some of the sediment back into the water layer (Fig. 1). The optimum dosage of CTAB was 0.1 to 0.2 g per 10 g sediment. The sediments with the optimum dosage were transferred onto the filter paper and treated with spraying 0.25 to 1.0 mL of hexane per 1 g sediment, resulting in the significant decrease in the water content to 21% at 1.0 mL hexane/g sediment.